Remove EGR to prevent carbon build up?

[XuperXero]

Has anyone considered this? Aside from PCV, this is also dumping carbons back onto our intake valves.

 

[rodmoe]

I am not aware this was on our NA cars ..

 

[Sekred]

EGR does play a part in the emission control system of the Ecoboost engines.
I am no expert on GDI engines but from research I has done, most if not all GDI engines use some form of EGR.
GDI engines operate with higher combustion chamber temperatures which increase nitrogen oxide levels, one of the emissions the EPA has decided is nasty for our healths. Recirculating exhaust gas lowers combustion chamber temperatures.
EGR is use at part load and part throttle position and not when the engine is at idle or at full load.

Looking at the Ecoboost engine I can not see any mechanical connection between the exhaust manifold and the intake which leads me to believe that it uses reversion to control the EGR.
What I think happens is that during the start of the intake stroke where both the intake and exhaust valve are open a small amount on overlap, the ECU varies the exhaust camshaft to hold the exhaust valves open longer than normal which cause the exhaust gas to flow back into the cylinder during the intake stroke.
Now the cylinder can only hold a set volume, the exhaust gas takes up some space that the intake air would normally occuply , to keep the AFR correct, less fuel is injected, a smaller bang results which lower combustion chamber temps.

GDI engines also run with hotter intake valve temps, no cooling fuel charge. Combine that with hot exhaust gas recirculation and you can see how any oil is going to bake itself to the intake valve.

From a purests point of view regarding engine design, EGR, particularly hot EGR is a freaking disaster, is a cheap nasty method of controlling nitrogen oxide emissions IMO.

 

[D1JL]

Oxides of Nitrogen not only is harmful to humans but also plants and animals too.
So it is something that is needed to control.
It is not like the old days where an EGR system was just bolted on.
It is now designed into the head and therefore cannot be defeated without a lot of work.



Dave

 

[rodmoe]

Oxides of Nitrogen not only is harmful to humans but also plants and animals too.
So it is something that is needed to control.
It is not like the old days where an EGR system was just bolted on.
It is now designed into the head and therefore cannot be defeated withOUT a lot of work.

Dave

I think thats what ya meant or am i reading it wrong..??

 

[D1JL]

I think thats what ya meant or am i reading it wrong..??

YES,
Corrected, thanks.



Dave

 

[Sourskittle]

I could be wrong, but "blow-by" is just a fact of life for a motor under the cylinder pressures we see. All the pressure in the crank case needs to be vented, if not, it will cause leaks like crazy and reduce power. By nature, oil finds its way about anywhere, it follows the pressure rushing out.

My solution, love it or hate, is going to be to loop all our crank vents into one tube, then use a Venturi port on the downpipe to create a vacuum ( think about the way soap is added to a pressure washer system ). When in boost, the higher the exhaust flow, the more vacuum. Any bit of oil that would have normally found its way into either my intake manifold or my catch can, will instead be burned inside the downpipe.

My beet friend did this on his 6.0L powerstroke and loves it. 10 months ago at a "cars and coffee", I saw a supercharged big block chevy in a foxbody mustang and he used the same system. I did ask him about it at the time, and he said, "its so simple, unless your a tree hugging hippie or something, I can't imagine why all force inducted cars are not like this". Of course... He has a SC big block, he's not really winning any "save the world" awards, lol, but it showed it works well on gas and diesel engines.

And I did read about sky-activ putting exhaust back through the intake charge while the intake valves are left open an extra zilla-second. Pretty cool.

 

[Sekred]

More research and an update.
I think the info I supplied is incorrect, at least regarding the Ecoboost engines(s).
Can't find any Accurate information to confirm the 1.6 runs EGR, a few articles going back to 2010 where Ford where considering cooled EGR for the next generation of the Ecoboost platform.

 

[XuperXero]

EGR does play a part in the emission control system of the Ecoboost engines.
I am no expert on GDI engines but from research I has done, most if not all GDI engines use some form of EGR.
GDI engines operate with higher combustion chamber temperatures which increase nitrogen oxide levels, one of the emissions the EPA has decided is nasty for our healths. Recirculating exhaust gas lowers combustion chamber temperatures.
EGR is use at part load and part throttle position and not when the engine is at idle or at full load.

Looking at the Ecoboost engine I can not see any mechanical connection between the exhaust manifold and the intake which leads me to believe that it uses reversion to control the EGR.
What I think happens is that during the start of the intake stroke where both the intake and exhaust valve are open a small amount on overlap, the ECU varies the exhaust camshaft to hold the exhaust valves open longer than normal which cause the exhaust gas to flow back into the cylinder during the intake stroke.
Now the cylinder can only hold a set volume, the exhaust gas takes up some space that the intake air would normally occuply , to keep the AFR correct, less fuel is injected, a smaller bang results which lower combustion chamber temps.

GDI engines also run with hotter intake valve temps, no cooling fuel charge. Combine that with hot exhaust gas recirculation and you can see how any oil is going to bake itself to the intake valve.

From a purests point of view regarding engine design, EGR, particularly hot EGR is a freaking disaster, is a cheap nasty method of controlling nitrogen oxide emissions IMO.

Thanks for the detailed info, I'm not familiar with GDI engines myself and was unaware that this may be non-existent in components form.

If what you're saying is true about the exhaust valve overlap, then we should not need to worry about the EGR playing a roll in carbon build up as intake valve would be closed.

Layman's term: Good OCC is as far as we can go without adding port injectors.

 

[MOFiST]

I could be wrong, but "blow-by" is just a fact of life for a motor under the cylinder pressures we see. All the pressure in the crank case needs to be vented, if not, it will cause leaks like crazy and reduce power. By nature, oil finds its way about anywhere, it follows the pressure rushing out.

My solution, love it or hate, is going to be to loop all our crank vents into one tube, then use a Venturi port on the downpipe to create a vacuum ( think about the way soap is added to a pressure washer system ). When in boost, the higher the exhaust flow, the more vacuum. Any bit of oil that would have normally found its way into either my intake manifold or my catch can, will instead be burned inside the downpipe.

My beet friend did this on his 6.0L powerstroke and loves it. 10 months ago at a "cars and coffee", I saw a supercharged big block chevy in a foxbody mustang and he used the same system. I did ask him about it at the time, and he said, "its so simple, unless your a tree hugging hippie or something, I can't imagine why all force inducted cars are not like this". Of course... He has a SC big block, he's not really winning any "save the world" awards, lol, but it showed it works well on gas and diesel engines.

And I did read about sky-activ putting exhaust back through the intake charge while the intake valves are left open an extra zilla-second. Pretty cool.

Curious idea. At boost pressure the exhaust flow will be high so the venturi effect greater. How much turbulence would the give the exhaust flow or is it so minimal it would be a non issue? I've got an open mind and would be interested to see what you come up with.
*edit after reading up on the venturi effect I cannot say I fully understand how this and that tie together. But if it works wth.

 

[Slimer]

Layman's term: Good OCC is as far as we can go without adding port injectors.

This ^^^^^^^^